Treatment of Acute Myocardial Infarction

To the Editor: “Referral filter” bias can affect the generalizability of the results of any clinical trial 1 . The three clinical trials comparing angioplasty with thrombolytic therapy in the March 11 issue of the Journal did not mention the referral filter that led to the enrolled samples 2 – 4 . Physicians have no way of knowing whether the study populations are similar to their own patients without a clinical description of the patients who were excluded. Could the authors comment on the number of patients excluded and the reasons for exclusion? To the Editor: It is difficult to draw any firm . . .